The invention relates to an improvement in apparatus for moving a nozzle of an adhesive applicator between a storage position and a position for applying a adhesive.
U.S. Pat. No. 3,908,869 issued on Sept. 30, 1975 in the name of W. A. Little and is entitled Method and Apparatus for Dispensing Air-curable Viscous Materials. Such patent discloses apparatus and method for dispensing an air-curable material, such as a silicone rubber, without allowing the material to partially cure and clog portions of the dispensing system. Clogging of the system is avoided by immersing the dispensing end of the nozzle in a reservoir of liquid, such as oil, when the nozzle is not being used. The oil forms an air tight seal around the end of the nozzle. After the nozzle is immersed in the oil, all air-contacted material in the nozzle is purged from the nozzle into the oil and then a back pressure is applied to the material in the nozzle to draw part of it upwardly into the nozzle and thus draw some of the oil from the reservoir into the nozzle. The apparatus of the Little patent is described as useful for forming a silicone rubber gasket by removing the nozzle from the reservoir and passing it along a predetermined path above a work surface while dispensing rubber through the nozzle to thereby form the gasket.
It also is known to clean a nozzle that is moved through a series of liquids, such as liquids in test tubes, in order to prevent contamination of samples in the various test tubes. See, for example, U.S. Pat. No. 3,740,041 which issued on June 19, 1973 in the name of A. R. Jones for Reagent Mixing Apparatus.
U.S. Pat. No. 2,245,657 issued on June 17, 1941 to A. Eppler for Apparatus for Applying Adhesive to Shoe Parts, discloses a glue pot from which adhesive is pumped through openings leading into the central portion of a brush. When the use of the apparatus is to be discontinued for substantial period of time, the glue can be prevented from hardening in the brush by raising about the brush a cup or container having therein water or other liquids.
U.S. patent application Ser. No. 380,965, mentioned above, discloses a nozzle for an adhesive applicator mounted for movement between a storage position and a position for applying adhesive. In response to movement of the nozzle between its positions a sump is moved between a position for receiving an end of the nozzle (when the nozzle is moved into its storage position) and a position spaced from the end of the nozzle (when the nozzle is moved to its position for applying fluid). Such application also discloses automatically repositioning the nozzle in the sump during periods when the nozzle is not applying fluid. While the apparatus of such application is satisfactory for its intended function, it is desirable to provide a simplified, positive acting apparatus as disclosed herein.